Valve Software's latest shooter is Left 4 Dead, a cooperative attempt to fight off waves of zombies on the way to an escape point.

While it's horrifically fun, it also requires a few friends to get the most out of the experience. On the other hand, the few "campaigns" that the game offers might mean that gamers might wait for it to hit the bargain bin, so to speak.

Today, you can get the best of both worlds. Gamers will need to download the game from Valve's Steam store, which, admittedly, is going to take a while. Hopefully those of you on the West Coast can read this, start the download, then head off to work. The only problem is that you'll need to take a half day: the offer expires at 5 PM PDT.

Bonus: if you like it, Valve is offering the game for a discounted price of $23.99 for this weekend only.